Conductive materials can be used as gate electrodes in electronic devices as well as in other applications. For example, these materials may be deposited and optionally patterned on a substrate prior to coating or deposition of a dielectric material to form an electronic device.
Many electronic devices include a conductive gate electrode adjacent to a gate dielectric. Gate dielectrics act as insulators in electronic devices. Conductive materials can be coated with a dielectric or anodized for forming a gate dielectric adjacent to a gate electrode. Anodizable metals may be oxidized by traditional routes to develop porous or nonporous dielectric layers.
Nonporous or barrier dielectric layers are generally produced anodically in electrolyte solutions, which are relatively noncorrosive toward the conductive metal upon which the dielectric layer is grown. High quality dielectric layers generally are free of pin-holes, and have low leakage current, high breakdown field, and resistance to charge trapping. Barrier dielectric films generally are uniform in thickness.
Anodization of conductive materials, for example as metals, to form dielectric layers can be accomplished in a batch process. The conductive material may be immersed in an electrolyte solution at a certain temperature. An applied voltage can be applied to the electrolyte solution for a period of time to form a dielectric layer on the conductive material as described, for example, in U.S. Pat. No. 6,267,861 (Kinard et al.).
The formation of dielectric layers on anodizable materials may be used for numerous applications in electronic devices including electrolytic capacitors, rectifiers, transistors, diodes, light emitting devices, resistors, and combinations thereof.